Vion Pharmaceuticals Inc has announced the initiation of a Phase I intravenous (IV) human clinical trial of its Tapet bacterial vector (Tumor Amplified Protein Expression Therapy) at Beth Israel Deaconess Medical Center (BIDMC) in Boston and the Cleveland Clinic Foundation.

The Phase I study is expected to enroll up to 20-30 patients. Michael Atkins, MD at the BIDMC and Ronald M. Bukowski, MD at the Cleveland Clinic will serve as principal investigators.

Both are highly respected clinical investigators and have considerable

experience in the treatment of cancer with biological agents. These sites are in addition to Phase I intravenous trials currently being conducted under similar protocols at the National Cancer Institute, in Bethesda, Maryland and The Royal Marsden Hospital in the United Kingdom.

The Phase I studies are designed to determine the safety and tolerability of TAPET in a broad group of patients with advanced cancer, and to provide information regarding Tapet 's ability to penetrate and preferentially replicate and accumulate within tumours of selected patients.

Alan Kessman, president and CEO of Vion, noted, "We are pleased with the progress of the Tapet clinical trials to date. The design of the current

study is similar to the ongoing trials, and will give the company additional information on safety, dose-response relationships, kinetics of bacterial infection and clearance, and biological effects. Data from the study may also provide a solid scientific and clinical foundation for future human clinical trials using 'armed' Tapet vectors, 'unarmed' Tapet vectors, and 'unarmed' Tapet vectors in combination with standard anticancer agents."

Tapet is the designation for Salmonella bacteria that have been genetically altered to reduce or prevent the usual consequences of infection. In extensive preclinical studies, TAPET bacteria have been shown to accumulate preferentially in tumors, inhibiting their growth. Scientists at both Vion and Yale University have demonstrated the antitumour activity of TAPET in mouse models.

Toxicology studies have been conducted in several animal species including monkeys, and these studies have shown that administration of high doses of Tapet is safe and well tolerated. Vion scientists have also demonstrated the capacity of the Salmonella in preclinical studies to carry and express genes coding for therapeutic anticancer agents, thus permitting the delivery of the anticancer agents to tumors in high concentrations while avoiding toxicity to normal tissues.

The company recently received a US patent on its Tapet technology, which covers the Salmonella bacterial vectors carrying a genetically modified msbB gene to reduce virulence as well as pharmaceutical compositions containing the Salmonella.

Vion Pharmaceuticals Inc is a biopharmaceutical company engaged in the research, development and commercialization of cancer treatment technologies.